Organophosphate pesticides as diazinon disrupt the neuroimmune communication, affecting the innate and adaptive immune response of the exposed organisms. Since the target molecule of diazinon is ...typically the acetylcholinesterase enzyme (AChE), the existence of a non-neuronal cholinergic system in leukocytes makes them susceptible to alterations by diazinon. Therefore, the aim of this work was to evaluate the activity of AChE, acetylcholine (ACh) concentration, and the expression of nicotinic ACh receptors (nAChR) and muscarinic ACh receptors (mAChR) in spleen mononuclear cells (SMNC) of Nile tilapia (O. niloticus) exposed in vitro to diazoxon, a diazinon metabolite. SMNC were exposed in-vitro to 1 nM, 1 μM, and 10 μM diazoxon for 24 h. The enzyme activity of AChE was then evaluated by spectrophotometry, followed by ACh quantification by ultra-performance liquid chromatography. Finally, mAChR and nAChR expression was evaluated by RT-qPCR. The results indicate that AChE levels are significantly inhibited at 1 and 10 μM diazoxon, while the relative expression of (M3, M4, and M5) mAChR and (β2) nAChR is reduced significantly as compared against SMNC not exposed to diazoxon. However, ACh levels show no significant difference with respect to the control group. The data indicate that diazoxon directly alters elements in the cholinergic system of SMNC by AChE inhibition or indirectly through the interaction with AChR, which is likely related to the immunotoxic properties of diazinon and its metabolites.
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•OPs are capable of disrupting the cholinergic system of SMNC in Nile tilapia.•AChE activity is inhibited in SMNC exposed in-vitro to 1 and 10 μM of DXN.•DXN alters the expression of mAChR and nAChR in SMNC of Nile tilapia.•DXN inhibits AChE but also alters " non-conventional " targets such as AChR.
Diazinon is an organophosphate insecticide commonly used worldwide to chemically control different organisms considered as pests. In the past years, diazinon has been described to have immunotoxic ...effects in several species. Nile tilapia is a teleost fish with an ecological and economic importance, which is also one of the fishes with the highest consumption around the world. The aim of this study was to evaluate the production of neutrophil extracellular traps (NETs) from fish Nile tilapia (Oreochromis niloticus) exposed to diazinon (0.97, 1.95, and 3.91 mg/L) for 6 and 24 h. The results obtained indicate that the exposure to diazinon per se increases NETs production. Therefore, these results could be involved in the understanding of the inflammatory process induced by exposure to pesticides.
Diazinon (DZN) is an organophosphate pesticide characterized by inhibiting the enzyme acetylcholinesterase (AChE) (E.C. 3.1.1.7), affecting the nervous system. There is currently enough evidence ...proving this pesticide also affects the immune response; however, the immunotoxicity mechanisms through which these substances exerts toxic effects remain unclear. For that reason, this work evaluated the effect of diazinon on the intracellular calcium flux, ERK1/2 phosphorylation (pERK1/2), apoptosis, senescence, and mitochondrial membrane potential (ΔΨm) in spleen mononuclear cells (SMNC) of Nile tilapia, a teleost fish of commercial and ecological relevance. The results obtained indicate that diazinon causes significant damage in all evaluated parameters, which play an essential role in intracytoplasmic signaling of immune cells, suggesting these signal pathways could be related with the immunotoxicity mechanism of these type of pesticides.
•DZN provokes alteration in intracytoplasmatic signals.•DZN increases the flow of intracellular Ca2+ and ERK1/2 phosphorylation in leukocytes of Nile tilapia.•DZN causes loss of ΔΨm and induces senescence and apoptosis in fish leukocytes.
Nervous and immune systems maintain a bidirectional communication, expressing receptors for neurotransmitters and cytokines. Despite being well established in mammals, this has been poorly described ...in lower vertebrates as fishes. Experimental evidence shows that the neurotransmitter acetylcholine (ACh) regulates the immune response. In this research, we evaluated mRNA levels of muscarinic acetylcholine receptor (mAChR) in spleen mononuclear cells of Nile tilapia (Oreochromis niloticus) and compared the expression levels of immune cells with the brain. The mAChR subtypes (M2-M5A) were detected in both tissues, but mAChRs mRNA levels were higher in immune cells. This data have a potential use in biomedical and comparative immunology fields.
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•Cholinergic receptors are present on fish leukocytes.•Brain and spleen mononuclear cells express the muscarinic acetylcholine receptor subtypes M2, M3, M4, and M5A.•The mRNA levels of all the evaluated mAChR subtypes were higher on spleen mononuclear cells than the brain.
Spinosad and temephos are two of the most used pesticides in Mexico for the control of vector causing disease such as dengue, chikungunya and Zika. The aim of this study was to compare the neurotoxic ...effects of these two pesticides using guppy fish (Poecilia reticulata) as a model organism. Guppies were exposed for 7 and 21 days to technical grade temephos and spinosad at 1.0 and 0.07 g/L, respectively, (10 and 0.5 mg/L of active substance; concentrations recommended by the Ministery of Health of the State (Secretaría de Salud de Nayarit (SSN) Mexico)). Subsequently, acetylcholinesterase activity (AChE) and acetylcholine concentrations (ACh) in muscle tissue were determined. Temephos exposure decreased AChE activity and increased ACh concentration, whereas exposure to spinosad only increased ACh concentration. Though cholinergic alterations were more severe in fish exposed to temephos, both pesticides were equally lethal during the first seven days after exposure. Nonetheless, temephos was more lethal after 21 days.
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•Optimal conditions of oil extraction by thermosonication were found by RSM.•Thermosonication extraction improved oil yield and its quality was preserved.•Amplitude increase cause ...microstructural changes and reduce the crystallinity index•Structural changes in the residual cake caused by thermosonication were evidenced.
The seed of Ricinus communis L. is a source of oil that can be used to produce biodiesel. In this study, the thermosonication (TS) extraction of castor oil is proposed and is compared with Soxhlet (S) extraction as the conventional method. The optimum conditions for the TS extraction of castor oil were determined by response surface methodology (RSM). The time at 25, 35, and 45 min and amplitudes of 25, 50, and 75% were independent variables, while the dependent variables were the oil yield, iodine index, peroxide index, saponification index, unsaponifiable matter, acidity index, and refraction index. The optimal conditions for the oil yield were an amplitude of 50%, 35 min, and a solid/liquid ratio of 1/10 g/mL; a yield of 61.12% was reached under these conditions; by S extraction, the yield was 57.3% after 8 h of extraction. The microstructure of the residual cake before and after extraction was evaluated by scanning electron microscopy and the cellulosic compounds, proteins, and lipids in the residual cake were identified and their distribution observed by means of confocal laser scanning microscopy. Microscopy techniques and image analysis were helpful in evaluating the changes in the microstructure that occur on the residual cake during the TS and S extraction and to understand the extraction mechanisms. The crystallinity index was calculated from X-ray diffraction spectra to interpret changes in the structure of the residual cake before and after use of the extraction methods. Therefore, the TS extraction improved the oil yield in shorter extraction time. Characterization of the residual cake opens the way to study a potentially usable material as a source of cellulosic compounds.
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